Fill up the radiator and install a pressure tester. If it's leaking that bad you should see it squirting out.
Pay close attention to the intake manifold area, cylinder head
gaskets, freeze plugs and the heater hoses.
Make sure it is not leaking
out of the A/C drain, that would suggest...

My truck recently overheated and while adding coolant I found it leaking near the bell-housing. I have checked the freeze plugs, hoses and gaskets for possible leak source and cannot find anything. Would appreciate any advice you guys have to offer... hoping it's not a cracked block.

Which engine does your truck have?
Is it leaking on top of the bell-housing or out of the bottom?
I would pressurize the cooling system with a pressure tester, does it leak more when the engine is
cold or when it reaches operating temperature?